iMac Logic Board, Graphics and Power Supply Repair

When an iMac is dead, starts with its fans running but no picture, or cuts out at random, the parts to suspect are the power supply, the logic board and, on 2009–2011 models, the graphics card. All three can be repaired. We repair logic boards at component level from $449, replace power supplies from $399 on the 21.5-inch and from $479 on the 27-inch, and replace 2009–2011 graphics cards from $549. On every Intel iMac except the 2020 27-inch, your files sit on a separate drive that board work does not touch.

Board-level repair or a replacement board

A dead logic board rarely means the whole board has failed. More often one component has: a shorted capacitor, a failed voltage regulator, a damaged connector, or corrosion where liquid got in. Board-level repair means tracing the fault to that part and replacing it, which is the work this workshop has done since 2006 (our board-level repair page covers other devices). Board replacement means fitting a used or refurbished board from another iMac of the same model.

We diagnose before we quote. The hands-on bench diagnostic is always $150, waived if you go ahead with the repair, and if a fault is not economic to fix we say so. Everything else we do on these machines is on our iMac repair and upgrades page.

The 2020 27-inch is different

On the 2020 27-inch, storage from 256GB to 2TB is soldered onto the logic board and managed by the T2 chip. There is no separate drive to lift out, so a replacement board arrives with its own empty storage and your files stay on the old one. On this model, repairing the original board is how you keep your data. It is also why we cannot upgrade a 2020's internal SSD and suggest an external Thunderbolt SSD instead. More on this model is on our 27-inch 5K 2019–2020 page.

The power supply is a separate part

Every Intel iMac from 2009 to 2020 has its power supply as its own unit inside the case. Mains power goes into the PSU, and the PSU feeds the logic board. From outside, a dead PSU and a dead board look identical: you press the button and nothing happens. Inside, they are different parts at different prices, so telling them apart is the first job on the bench.

The 2009–2011 iMacs have diagnostic LEDs on the logic board, and LED 1 shows trickle power from the supply. It stays lit whenever the iMac is connected to mains, even switched off. If it is dark with a known-good cable and outlet, the usual diagnosis is a failed power supply, a repair from $399 or from $479 rather than a board. On later models we test the supply's output directly.

The 2011 27-inch and its Radeon HD 6970M

The 3.1GHz Core i5 and 3.4GHz Core i7 versions of the Mid 2011 27-inch were fitted with an AMD Radeon HD 6970M (1GB, or 2GB as an option). Apple ran an iMac Graphics Card Replacement Program for units sold between May 2011 and October 2012, covering them for three years from purchase. The symptoms it listed were a display that is distorted, white or blue with vertical lines, or that goes black. The program expired years ago, so any repair now is at the owner's cost.

To see which card yours has, choose About This Mac from the Apple menu and read the Graphics line. The 2.7GHz 27-inch has a Radeon HD 6770M, which was not part of the program, although any card can fail. The fix is a replacement MXM graphics card, from $549. You may see cheap "reflow" offers, where the graphics chip is heated to remake its solder joints; that can bring a card back for a while, but the fault tends to return, which is why we quote a replacement card.

2009–2011 graphics cards and Metal upgrades

The 2009–2011 iMacs with discrete graphics use an MXM 3.0 module, a graphics card that plugs into the logic board, so a failed GPU is a card swap rather than a new board. The base Late 2009 21.5-inch uses NVIDIA GeForce 9400M graphics that share system memory, and has no card to swap. From Late 2012 on, graphics are part of the logic board, so a graphics fault on those models is board-level work.

Owners also replace cards that still work. The original ATI and AMD cards in these iMacs are not Metal-capable, and OpenCore Legacy Patcher, the tool that installs newer macOS on Macs Apple has dropped, recommends a Metal GPU for them. With the stock card, newer macOS relies on non-Metal patches: from Monterey, Maps and Find My break, DRM video will not play in Safari, and Zoom needs a patch. The community has worked out how to fit later, Metal-capable cards. If you are considering one, know this:

• Size. 21.5-inch models take MXM-A cards only. 27-inch models take MXM-A or the larger MXM-B, which needs heatsink changes.
• Firmware. Cards not made for Apple need modified firmware (a flashed vBIOS). Without it, as one iFixit Answers reply puts it, the result is simply a black screen.
• The processor stays the same. 2009–2010 models lack AVX and 2011 models lack AVX2, and some newer apps will not run without them. On Ventura and later the patcher has to work around the missing AVX2 for AMD Polaris and Vega upgrade cards, and it lists Navi cards as unsupported.
• It is community practice. Apple never supported any of this. Results depend on the exact card, its firmware and the iMac, and the knowledge comes from user forums and repair guides, not a manufacturer.

Graphics card replacement starts from $549, and we quote the card options that suit your model along with what each means for newer macOS. If a newer macOS is the goal, read newer macOS on an old iMac before choosing, and see our 2009–2011 iMac page for the rest of what these models can take.

Backlight circuit faults

A backlight fault looks like a dead screen, but the iMac is running: the fans spin, older models chime, and the Caps Lock light on a wired keyboard responds. Shine a torch at the glass in a dim room. If the desktop or login window is faintly visible, the LCD works and the light behind it does not. The cause is either the backlight driver circuit, which on many models is part of the logic board, or the LED strip inside the panel. The first is a board-level repair from $449; the second needs a new display, priced on our iMac screen replacement page. On a 5K, telling them apart is the difference between a repair from $449 and a new display from $1,099 (2014–2017) or from $1,199 (2019–2020).

What it costs, and when it is not worth it

Values are typical private asking prices on Gumtree in September 2026. A new 24-inch M4 iMac is $2,399, so a board repair from $449 on a 2019 or 2020 costs a little under a fifth of replacing it and keeps a bigger screen. On a 2011 27-inch the maths runs the other way: the repair costs more than the machine would sell for, and it stays on High Sierra unless patched. We will still do it if the iMac matters to you, but we will not call it an investment. Model details are on our 27-inch 2012–2013 and 27-inch 5K 2014–2017 pages, and our guide to repairing or replacing an old iMac works through the decision.

Jobs we will tell you not to do:

• A second major repair on a 2009–2011 iMac that has already had one. Two repairs, each from $449, cost more than the asking price of a used 2019 27-inch 5K.
• A replacement board on a 27-inch 2012–2013 worth about $220, unless you have a particular reason to keep that machine.
• Extensive board work on an iMac with corrosion spread across the board, where the sensible aim is usually to recover the data and move on.

If the board on a 27-inch 5K from 2014 to 2020 is beyond saving but the display is fine, the panel can live on as a standalone 5K monitor with a third-party driver board, which costs about $449 in Australia for the board. Against $2,599 for a Studio Display, that is worth asking about.

Call 0400 454 859

Your data during board work

From 2009 to 2019, iMac storage is a separate part: a hard drive, an SSD, a blade SSD, or a Fusion Drive made of a blade SSD and a hard drive working as one. Board repair and board replacement leave it alone, and your files are there when the iMac comes back. Two cautions:

• Fusion Drives are a pair. Replace either half and the pair shows up as two separate drives, and Apple's command to rejoin them permanently deletes all data. Nothing should be reset or erased until your files are safe.
• The 2020 27-inch is the exception described above: the storage is on the board, so repairing the board is the route to your data.

If the iMac cannot start but the drive is readable, we can copy your files off, from $249, before any board work; see data recovery. After a liquid spill, switch off at the wall, unplug, and do not try to start it again until it has been checked. If you are still working out what is wrong, our iMac won't turn on guide has checks you can do first, and iMac repair costs puts every price in one place.

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Questions

How much does it cost to fix an iMac logic board?

Our board-level repair starts from $449, and a replacement logic board starts from $699, quoted by model. Other Australian shops publish entry prices for board repair of roughly $320 to $450, with harder jobs running past $900, so our starting price sits near the top of that entry range. Board faults need hands-on diagnosis first, and our bench diagnostic is always $150, waived if you go ahead with the repair.

Can an iMac power supply be replaced?

Yes. On every Intel iMac from 2009 to 2020 the power supply is a separate unit inside the case, so a failed one is replaced without touching the logic board. We charge from $399 on the 21.5-inch and from $479 on the 27-inch. On 2012 and later models the glued display has to come off to reach it, so the price includes new display adhesive.

Can a power surge damage an iMac?

Yes. A surge from a storm or a faulty appliance can damage the power supply, and sometimes the logic board behind it. Because the supply takes the mains side, it is the first part we test after a surge. A surge-protected power board lowers the risk but does not remove it. If your iMac died during a storm, tell us when you ring.

Does Apple still fix 2011 iMac graphics cards for free?

No. Apple's iMac Graphics Card Replacement Program for the Mid 2011 27-inch with the Radeon HD 6970M covered units sold between May 2011 and October 2012 for three years from purchase, so it expired long ago. Any repair now is at your cost. We replace the MXM graphics card from $549, and can quote Metal-capable options if you want to run newer macOS.

Can I upgrade the graphics card in my iMac?

Only on 2009–2011 models with discrete graphics, which use a removable MXM card. The community fits later, Metal-capable cards to them, which helps with newer macOS through OpenCore Legacy Patcher, but non-Apple cards need modified firmware and results vary by card. From Late 2012 onward the graphics are part of the logic board, so there is no card to upgrade.

Will a logic board repair delete my data?

Not on iMacs from 2009 to 2019, where the drive is a separate part that board work does not touch. The 2020 27-inch is different: its SSD is soldered to the logic board, so a replacement board would leave your files behind on the old one, and repairing the original board is how you keep them. A backup beforehand is sensible either way.

How long does an iMac logic board repair take?

It depends on the fault and on parts, so we give you a timeframe with the quote rather than promise a day. Board-level work starts with finding the failed component, which for intermittent faults can mean running the iMac for a while to catch it. Power supplies and graphics cards depend on stock for your exact model.